Oven venting system



Oct. 16, 1962 T, H,'sw|sH|= 'R 3,059,089

OVEN VENTING SYSTEM Filed Nov. 29. 1960 FIG. 5

INVENTOR. THOMAS H. SWISHER BY @MM/.

ATT Y.

' between the inner and outer oven walls.

3,059,089 GVEN VENTENG SYSTEM Thomas H. Swisher, Elmhurst, Ill., assigner to General Electric Company, a corporation of New York Filed Nov. 29, 1960, Ser. No. '72,422 8 Claims. (Cl. 21g-35) This invention relates to cooking ovens and more particularly to venting arrangements for these ovens.

It is quite well known that ovens used for baking or broiling require air circulation into, through and out of their interior to insure uniformly acceptable results. Baking operations are quite dependent on good convection heating, and generate substantial volumes of vapor which must be vented, while broiling may be productive of greasy smokes which should be discharged from the interior of the oven. In conventional cabinet or free standing ranges, the baking vapors are usually vented by means such as disclosed in Berg U.S. Patent 2,569,652, granted October 2, 1951, for Oven Vent for Ranges. For broiling, the oven door is left slightly ajar. rThe Berg construction is not useful with the presently popular builtin oven, whereupon elaborate and expensive venting arrangements such as disclosed in Hupp U.S. Patent 2,739,584, issued March 27, 1956, have been considered necessary.

It is therefore an object of the present invention to provide a simplified method of providing an effective air ilow pattern in ovens of boththe cabinet range and builtin types.

It is another object of the invention to provide an oven air ilow pattern which is characterized by the entry of air at the bottom rear wall of the oven, and its exit through a passage which is disposed at, and preferably coextensive with, the upper edge of the oven door, thereby providing a basically diagonal air pattern along which ydiffusion and circulation patterns will occur by reason of convection currents induced by the oven heating elements.

It is a further object of the invention to utilize as intake air passages through the rear oven wall, ports in the oven bake unit electrical terminal block.

It is a still further object of the invention to provide an oven air exhaust passage by inverting the conventional gasket seal about the door frame whereby the gasket extends across the bottom and up the sides of the door frame, but is discontinuous adjacent the upper edge of the door.

To achieve these objects, the invention contemplates the use of an oven of either the built-in type or of the type which is integral to a free-standing range. In either event, the outer rear wall of the oven is positioned such that it is sufficiently in communication with the ambient air to allow air to be drawn through suitable apertures in this outer rear wall by the chimney effect induced by the oven when heated. A highly effective passageway for admitting air from the rear outer wall into the oven cavity utilizes the terminal block of the lower oven heating unit. The terminal block at one end nominally protrudes through the rear inner wall of the oven into the oven cavity and at the other end extends into the section The end of the block within the oven cavity also includes sockets housing the contact elements for receiving the blade-like terminals of the lower heating element of the oven. The terminal block of the present invention is provided with air passages positioned laterally outwardly of the terminal sockets. These passages extend horizontally from the rear of the terminal block through the block to ilow into downwardly directed branches adjacent the front or inward end of the terminal block. Each downwardly directed branch is llared to disperse air currents in a Widening pattern against or at least toward the oven oor. The

3,959,089 Patented Oct. 16, 1962 air will then rise due to the heating of the air Within the oven and will be exhausted near the upper edge of the door.

To .achieve the required results, the invention employs the door sealing gasket as the means of air egress. This gasket is affixed to the door frame to contact the door on closure about the periphery of the door to virtually isolate the oven cavity from the ambient surroundings. As used herein, the gasket is discontinuous within a sector adjacent the top edge of the door providing an air gap between the gasket ends. This construction allows passage of exhaust air through the gasket in this area only.

in an alternate embodiment (not shown in the drawings), suitable debosses are formed in the upper edge of the door about `a continuously formed gasket to provide one or more air passages circumventing the adjacent gasket.

The invention both as to its organization and principle of operation, together with further objects and advantages thereof, will best be understood by reference to the following specification taken in connection with the drawings in which:

FIG. l is a front elevational view of an oven with the door in the fully open position;

FIG. 2 is a side sectional elevation taken along the lines 2 2 of FIG. l showing the door in the fully closed position as it would be during a baking operation;

FIG. 3 is .a top sectional View of a terminal block as used herein. This view may be considered as taken along the lines 3 3 of FIG. 4;

FIG. 4 is a front elevational view of the terminal block of FIG. 3;

FIG. 5 is a side sectional elevation of the terminal block as viewed from lines 5 5 of FIG. 3; and

FIG. 6 is a possible configuration of the outer rear panel to provide air intake louvers.

In FIGS. l and 2 there can be seen the oven 10 embodying my invention. The oven includes an inner cabinet formed of sheet metal walls 12, outer appearance casing 14 and a layer of insulation 15 separating the inner cabinet from the outer casing. The inner cabinet encloses a rectangular polyhedron cavity 16 and internally within the cavity an upper horizontal heating unit 18 and a lower horizontal heating unit 20. The front of the oven is provided with an access opening which is normally covered by bottom hinged door 22. The door includes an inner lining ,and an outer appearance panel spaced from the inner lining by suitable air space partially filled with insulation. In FIG. 1, this door 22 is shown in its fully open position angled horizontally from the oven frame 24 and in FIG. 2, the door is shown in the fully closed position suitable for baking or broiling. Above the upper front surface of the door frame, there is provided a vertical extension on the casing which houses the control panel 26. Extending outwardly from this panel are suitable knobs 28 for manually controlling the functioning of the heating units in any known manner.

The heating units 1S and 20 are of the generally known sheathed type, each 0f which comprises a coiled resistance conductor housed in a metallic sheath and supported in uniformly spaced relationship to the sheath by a highly compacted mass of suitable heat conducting and electrially insulating material such as powdered magnesium oxide.

' Each heating unit usually comprises a sheath confgurated of each unit may be of the male plug-in type which include bayonet ends for mating with female contactors within a suitable refractory material terminal block. For

heating unit 18, there is provided a terminal block 36 which is affixed to the outside of the oven rear inner wall 3S at a position just below the inner ceiling 40v of the oven cavity. Block 36 protrudes through rear Wall 38 into the cavity so that the terminal receiving connectors (not shown) are open to receive the terminals. At the back of the terminal block suitable wires 50 are connected to supply the terminal block connectors and the control mechanism with an electric power source. The heating unit, as mentioned, is of the plug-in type which may be detached from its mating connection to the connectors `for the purpose of cleaning by drawing the unit in the forward direction with simple slide motion along guard rails 51 and out the access opening.

' The other heaing unit Z0 which is positioned in a horizontal plane just above the cavity floor 52 is also of the type which at its innermost ends includes male terminals (not shown). The heating unit 2@ is designed to slide along guard rail 53 so that the terminals may engage the suitable female sockets Within terminal block 56 (shown in detail in FIGS. 3 5). This terminal block is preferably molded of suitable refractory material and includes the sockets 57 which face the front of the oven cavity. The terminal block includes a shoulder section 53 which abuts against the inner wall 38 of the oven and is secured there by suitable screws 59. This terminal block differs rfrom block 36 previously described in that inwardly of these shoulder sections, the terminal block is formed with the leg portions eti, which project rearwardly into the inter-wall air space to about t from the lrear outer wall of the casing. Positioned above and slightly outwardly of these rear channel legs the outer wall may be provided with louvers `61 or other suitable air inlet openings (FIG. 6) to allow air passage from the external atmosphere to the inter-wall area. In this area adjacent the terminal block, insulation should be thinned out to allow this air passage to reach the terminal block legs with minimum of obstruction to the air iiow. In the normal fabrication of an oven many air openings remain in the outer rear wall due to mounting holes, `and minor gaps between adjacent surfaces. It has been found that such openings usually supply sufficient venting air without louvers or openings specifically designed for air venting. Louvers or openings specifically provided for inlet of air are however preferable.

The three forwardly facing connector sockets 57 each individually accommodate a suitable tensioned blade con- L.

nector 62 for good electrical contact with the terminals (not shown) of the heating unit Ztl, as well known in the art. The terminal block, as mentioned, includes projecting legs 60 each of which is arranged to provide an air passage channel 64. Each channel may exhibit a square cross-section inlet opening with sides which should be generally in the range of 1/2 in length. Thus an air intake area of 1A inch is provided by each channel totaling about 1/z inch of intake area to the oven cavity. Each of these open channels extends horizontally from the rear wall of the terminal block to a position adjacent the front thereof. At this position, each channel is angled normal to the horizontal to form a flared, downwardly open mouth 65. In this way, air may enter and pass through this inwardly directed horizontal channel, and then downwardly through the flared mouth into the oven cavity.

To provide an air exit from the cavity, there is secured to the door frame about the periphery of the door an enclosing or sealing gasket 70. The gasket may be fabricated from an extruded strip of silicone rubber which is shaped to conform in its lateral extent with the outline of the periphery of the access door 22. The gasket may be generally of known design including in its cross-sectional area a base adapted to adhere by suitable adhesion means to the adjacent oven frame and also including a thin flexible iiap extending from the base. The iiap extends sufliciently to be contacted by the door and also must be sutliciently flexible to be deformed by the pressure exerted against it by the door when in its closed position. By the use of such gaskets, there is lformed a substantially air impervious seal between the oven door and the door frame to effectively isolate the oven cavity. In the present invention, a gasket strip is adhered to the door frame so that a gap 73 of from three to five inches exists between the gasket ends 71 and 72 adjacent the top center of the door. Thus when door 22 is in its closed position, the bottom and sides of the door cooperate with gasket 7i) to form a substantially air impervious seal While the discontinuous top sector of gasket 70 allows an air passageway 73 from the oven cavity past the top of the door to the ambient surroundings. With the door in the closed position this air passageway will extend for three to tive inches laterally and about 1A of an inch forward to allow about one inch of air escape area. This escape area, it may be noted, is considerably greater than the intake area of 1/z to allow for the expansion of air within the heated oven cavity.

Concerning the alternate embodiment previously referred to, in place of the gap between gasket ends, suitable debosses (not shown) in the door adjacent the gaskets upper extent could be provided. Presently, many manufacturers utilize such debosses to exhaust air from the oven cavity. These debosses nominally comprise concavities circumventing the gasket. These debosses include declivitous openings on either side of the gasket sloping to a passage of sufficient depth to remain clear of the gasket and thereby provide an open passage through the deboss. As mentioned, Stich debosses are in general use on ranges presently manufactured.

'ln operation, the oven heating units 18 and 20 individually or jointly tend to heat the air within the oven cavity Ithus inducing air iiow by means of the generally known chimney etiect of a heated space which has an exhaust opening above the -heat source. Due to this eiect, cool air will be `drawn into louvers 61 in the lower part of the rear outer wall and into the adjacent air channel openings. The air will then ow through the channel 6dland out its `downwardly directed mouth 65 Lto strike Ithe rear part of `oven cavity floor 52. The cool air will then rise and flow across the oven toward the exhaust opening. The now heated air will rise toward the upper `door periphery for exhaust to the surroundings through gap '73 in the discontinuous gasket.

in this manner `an air iiow is induced by natural air heating currents which will traverse the entire oven cavity diagonally to exhaust through the oven front.

While there has been described what is at present considered to be the preferred embodiment of the invention, it should be understood .that it is intended to erover in the `appended claims all modifications which fall within the true spirit and scope of the invention.

What is claimed is:

l. An electrically heated oven construction dening a rectangular hollow cavity, a lateral heating element located marginally above the bottom of said cavity, a hinged closure door normally closing rthe mouth of said cavi-ty; means for securing a constant flow of cooling air through said cavity when said heating element is energized `and heating said cavity, comprising: a terminal block protruding into said cavity from the rear thereof for conductively accommodating said heating element and for connecting said element to an energizing source, air passages through said terminal block to direct a stream of air downwardly into said roven cavity, means adjacent the periphery of said door for cooperating with the door in the closed position for isolating said cavity, and an air escape through said isolating means adjacent the `top of said cavity to allow air escape from said cavity tothe ambient atmosphere.

2. An electrically heated oven construction dening a rectangular hollow cavity, a lateral heating element located marginally above the bottom of said cavity, 'a hinged closure door normally closing the mouth of said cavity; means for securing `a constant ow of cooling `ait through said cavity when said heating element is energized and heating said cavity, comprising: a terminal block protruding into said cavity from the rear thereof for conductively accommodating said heating element and including means for connecting said element to an energizing source, air passages through said terminal block positioned outwardly of said connecting means for directing a stream yof air through the rear wall of said cavity and idownwardly into said cavity, means adjacent the periphery of said door for air sealing said door to disrupt air passage from said cavity about said door, and `an 4air passage through said sealing means adjacent the top of said door to allow air escape from said cavity above said door.

3. In a cooking oven having a rectangular cross-section polyhedron outer appearance cabinet, Ian inner cavity rdelined by circumscn'bing walls spaced from said cabinet, a liront opening in sai-d cabinet for allowing access to said cavity, and a hinged `door for covering said opening; a heat source within said cavity, means for supplying power to said source through the rear inner wall of said cavity, said power supplying means including a plurality of lateral ducts communicating with the interior of said cavity, air intake openings in the rear Wall of said appearance cabinet adjacent the outermost ends of said ducts, said outermost duct ends open to allow air 'to flow through said openings into said ducts, downwardly directed exits from said iducts for directing the ow of inlet therethrough Itoward the floor of said cavity, and means for exhausting air from said cavity from about the top` of said front door.

4. In a cooking oven having an outer appearance cabinet, yan inner cavity defined by circumscribing rectangular walls spaced from said cabinet, a front opening in said cabinet for allowing access to said cavi-ty, and a hinged door @for covering said opening, means vfor forming yan airtight seal between said door and the cabinet adjacent thereto, a heat source within said cavity, means .tor supplying power to said source through the rear inner wall of said cavity, said power supplying means including a plurality of lateral ducts communicating with the interior of said cavity, air intake openings in the rear wall of said appearance cabinet adjacent the outermost ends of said duets, said outermost duct ends open to allow lair to flow through said openings into said ducts, downwardly directed exits from said ducts for directing the flow of inlet air therethrough toward the floor of said cavity, said heat source when actuated drawing an intake of cool -air through said ducts into said cavity, and means for exhausting heated air from the top of said cavity toward the front thereof for causing a draft substantially traversing said cavity.

5. In a cooking oven of the type which includes a rectangular cavity formed of adjoining inner Walls, outer walls spaced from said inner walls and insulated therefrom, a front opening in said oven providing free access to said cavity from the exterior of said oven, a door movable from an open position allowing access to said cavity to a closed position isolating said cavity from the exterior thereof, and a heating unit spaced laterally Within said -cavity near the bottom thereof for connection to an energy source through the rear wall of said cavity, means for inducing a iiow of cooling air through said cavity comprising, a plurality of apertures in the outer rear wall of said oven, rneans providing air passages through said rear inner cavity wall adjacent said heating unit, channeling means in said lair passages for deflecting air within said passages downwardly into said cavity directed toward the bottom of said cavity, and means for providing an air passage at the upper juncture of said door iand the adjacent oven wall to allow air from said 4oven cavity to escape therethrough.

6. In a cooking oven of the type which includes a rectangular cavity `formed of adjoining inner walls, outer walls spaced from said inner walls and insulated therefrom, a front opening in said oven providing free access to said cavity from the exterior of said oven, a door movable from an open position allowing access to said cavity to a closed position isolating said cavity from the exterior thereof, and a heating unit spaced laterally within said cavity near the bottom thereof for connection to an energy source through the rear wall of said cavity, means -for inducing a ilow of cooling air through said cavity comprising, a plurality of apertures in the outer rea-r wall of said over, a terminal block protruding through said rear inner cavity wall, female electrical connection members within said yblock yfor receiving said heating unit for connection to said energy source, channeling means in said terminal block communicating between the interior of said cavity and said apertures to allow air passage from said apertures into said cavity, and means `for providing an air passage at the upper juncture of said door and the adjacent oven wall to allow air from said oven cavity to escape therethrough.

7. In a cooking oven of the type which includes a rectangular cavity formed of adjoining inner walls, outer walls spaced from said inner walls and insulated therefrom, a front opening in said oven providing free access to said cavity from the exterior of said oven, a door movable rorn an open position allowing access to said cavity to a closed position isolating said cavity from the exterior thereof, and a heating unit spaced laterally within sai-d cavity near the bottom thereof for connection to an energy source through the rear wall of said cavity, means for inducing a ilow of cooling air through said cavity comprising, a plurality of apertures in the outer rear wall of said oven, a refractory block protruding through said rear inner cavity wall, electrical connectors within said block for -connecting said heating unit to said energy source, channels in said block on either side of said connectors for providing communication between the interior of said cavity and said apertures to allow air passage through said apertures to said cavity, and means for providing an air passage at the upper juncture of said door and the adjacent oven -wall to allow air -from said oven cavity to escape therethrough.

8. In a cooking oven of the type which includes a rectangular cavity formed of adjoining inner walls, outer walls spaced from said inner walls and insulated therefrom, a front opening in said oven providing free access to said cavity yfrom the exterior of said oven, a door movable from an open position allowing access to said cavity to a closed position isolating said cavity from the exterior thereof, and a heating unit spaced laterally within said cavity near the bottom thereof `for connection to an energy source through the rear wall of said cavity, means yfor inducing a ow of cooling air through said cavity comprising, a plurality of apertures in the outer rear wall of said oven, a terminal block protruding through said rear inner cavity wall and including connectors for connecting said heating unit to said energy source, channels within said protruding block positioned outwardly of connectors and communicating between the interior of said cavity and said apertures to allow air passage from said apertures to flow into said cavity, said channels each including a horizontal path leading into a downwardly directed ilared opening for releasing air drawn thereinto near the floor of said cavity, and means for providing an air passage at the upper juncture of said door and the adjacent oven wall to allow air from said oven cavity to escape therethrough.

References Cited in the le of this patent UNITED STATES PATENTS 2,846,557 Schulze et al. Aug. 5, 1958 FOREIGN PATENTS 2,546 Sweden Dec. 13, 1890 

